Changing from a 4-Way Flat to 7-Way Blade Trailer Connector on Trailer and 2003 Ford Ranger
Question:
I have a 4 way flat car connector to a 4 way flat trailer connector, works OK. I want to change these to either a 6 way or 7 way round for easier hookup. Whichever you would recommend. I need a list of parts/adapters, or whatever it takes to get me there. 2003 Ford Ranger XLT X-CAB V6
asked by: THE O
Expert Reply:
First I recommend going with a 7-Way blade style for your trailer and truck because that is the most common advanced function connector used. To add one on the trailer you can use # PK12706. If your trailer only has the basic light functions then you will only need to cut off the 4-Way and attach the wires according to the diagram I have included.
Please note that when you attach the existing wires to the connector you cannot just go by wire color. You will need to go by function in then place the wires in the correct position according to the diagram. To determine the wire functions you can look at the existing trailer 4-Way. The one covered pin is the ground. Next to that is the running light wire. Then the left turn/brake light wire, and the last pin is the right turn/brake light wire.
For your 2003 Ford Ranger you will need to use # 37185. You will just plug in your 4-Way to the compatible end on this adapter, ground the white wire to the truck frame, and mount the connector. The remaining wires are purple for reverse lights, black for 12 volt power, and blue for electric brakes.
If you need all of those functions I have included a link to an FAQ article that will help.

Products Referenced in This Question
Adapter 4-Pole to 7-Pole and 4-Pole
- Trailer Wiring
- Wiring Adapters
- Multi-Function Adapter
- 4 Flat
- Plug and Lead
- 4 Flat
- 7 Round - Blade
- Hopkins
more information >
Pollak Black Plastic, 7-Pole, RV-Style Trailer Connector - Trailer End
- Trailer Wiring
- Trailer Connectors
- Trailer End Connector
- Plug Only
- 7 Round - Blade
- Pollak
more information >
Product Page this Question was Asked From
Replacement Custom Multi-Tow 7-Way and 4-Way Trailer Connectors
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Vehicle End Connector
- No Converter
- No Tow Package
- 4 Flat
- 7 Round - Blade
- Plug and Lead
- Plug-In
- Hopkins
more information >
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Shop: Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
- Shop: Dexter Trailer Hub and Drum Assembly for 3,500-lb Axles - 10" Diameter - 5 on 5 - Pre Greased
- Video: Comprehensive Review: Wire Loom, 1/2" Diameter (per Foot)
- Video: All You Need to Know About the Wire Loom, 1/2" Diameter (per Foot)
- Article: Trailer Wiring Diagrams
- Q&A: Distance From Wheel Mount Surface To End Of EZ-Lube Grease Cap On EZ-Lube Hub And Drum Assy
- Q&A: Parts Needed to Add Brakes to 2023 Big Tex 35SV Single Axle Trailer
- Q&A: Availability of Dexter Axle Brake Assemblies K23-026-00 and K23-027-00
- Shop: Karrier ST205/75R15 Radial Trailer Tire - Load Range D
- Q&A: My Vehicle has a 4-Pin Trailer Plug, but Trailer has 7-Pin Trailer Plug
- Shop: Adapter 4-Pole to 7-Pole and 4-Pole
- Shop: DeeMaxx Disc Brake Kit - 10" Rotor - 5 on 4-1/2 - Maxx Coating - 3,500 lbs
- Video: Setting up the Blue Ox Base Plate Kit on a 2016 Chevrolet Traverse
- Search Results: 7 way connector
- Shop: Blue Ox Base Plate Kit - Removable Arms
- Q&A: My Surge Brakes Are Activating When I Back Up My Trailer - What Can I Do?
- Q&A: Upgrading Big Tex #35SA Trailer With Brakes
- Q&A: Adding a 7-Way Trailer Connector to a Trailer
- Shop: 7-Way RV Upgrade Kit for Trailer Brake Controller Installation - 12 Gauge Wires
- Search Results: 23~468~469
- Search Results: fa1131822
- Search Results: 10~1~1
- Search Results: 7 way
- Search Results: wire loom clamp
- Search Results: akhd~550~35~ez~k
- Article: Brake Controller Installation: Starting from Scratch
- Video: Redarc Tow-Pro Liberty Brake Controller Installation - 2022 Toyota Sienna
- Video: Softride Locking Anti-Rattle Threaded Hitch Pin Road Test
- Video: Installation Guide for the Roadmaster Tail Light Wiring Kit for Towed Vehicles on a 2014 Honda CR-V